The present invention generally relates to constant velocity joints, and more particularly, to a vent for a constant velocity joint.
Constant velocity joints (CV joints) are common components in automotive vehicles. Typically constant velocity joints are employed where transmission of a constant velocity rotary motion is desired or required. The common types of constant velocity joints are a plunging tripod, a fixed tripod, a plunging ball joint and a fixed ball joint. These common types of constant velocity joints are either usually in a mono block style or disc style. Furthermore, these types of constant velocity joints currently are used in front wheel drive vehicles or rear wheel drive vehicles and on the propeller shafts found in rear wheel drive, all wheel drive and four wheel drive vehicles. The plunging CV joints will allow for axial movement during operation without the use of slip splines. Constant velocity joints are generally greased lubricated for life and sealed by a boot. Thus, constant velocity joints are sealed in order to retain grease inside the joint while keeping contaminants and foreign matter, such as dirt and water, out of the joint. To achieve this protection, the constant velocity joint is usually enclosed at the open end of the outer race by a sealing boot made of a rubber, thermoplastic, or silicone material. The opposite end of the outer race is generally enclosed by a dome or cap, known as a grease cap in the case of a disk type joint. A monoblock or integral stem and race design style does not use a grease cap. Instead it is sealed by the internal geometry of the outer race. This sealing and protection of the constant velocity joint is necessary because contamination of the inner chamber may cause internal damage of the joint. Furthermore, once the inner chamber of the constant velocity joint is lubricated, it is lubricated for life.
During operation, the constant velocity joint creates internal pressures in the inner chamber of the joint. These pressures have to be vented to the outer atmosphere in order to prevent pressure build-up which occurs during operation of the joint and may destroy the boot. If the pressure build-up is allowed to reach a critical state, the boot may crack and have a blow out thus losing sealability. Generally speaking a constant velocity joint is usually vented by placing a small hole generally in the center of the grease cap or at least one hole around the outer periphery of the outer race. These prior methods of venting the gas have some limitations because if the constant velocity joint is in a static state and not rotating, the lubricating grease may settle on the vent hole and block or hinder its function of venting any internal gas pressure. This type of vent may also allow the infiltration of contaminants into the internal chamber of the constant velocity joint. Furthermore, the constant velocity joint, after running for long periods of time, creates very high temperatures along with high pressures which are vented through the prior art vent holes. However, if the constant velocity joint is submerged or saturated in water or other contaminants, the water will, via a pressure differential, be sucked into the constant velocity joint thus contaminating the grease lubricant and possibly reducing the life of the constant velocity joint.
Therefore, there is a need in the art for a constant velocity joint that prevents the buildup of internal gas pressure while eliminating the ingress of contaminants from entering the constant velocity joint.
One object of the present invention is to provide a new venting solution for a constant velocity joint.
Yet a further object of the present invention is to provide a vent for a constant velocity joint that is capable of releasing gas under pressure to the atmosphere.
Yet a further object of the present invention is to provide a vent that prevents the entry of contaminants into the constant velocity joint.
Still a further object of the present invention is to provide a constant velocity joint that vents and allow equalization of pressure internally from the constant velocity joint relative to the atmosphere.
To achieve the foregoing objects, a vent for a constant velocity joint is disclosed. The constant velocity joint vent includes circumferential base and a cylindrical projection extending from an end of the base. The constant velocity joint vent further includes a circumferential flange extending from a surface of the projection. The constant velocity joint vent also includes a valve arranged on an end of the cylindrical projection opposite from the base. The valve is arranged such that it is made of a pliable material and is capable of allowing pressure to be released through the valve but to prevent the ingress of contaminants into the valve and constant velocity joint.
One advantage of the present invention is that the constant velocity joint includes a vent that allows for equalization of pressure from inside the constant velocity joint to the atmosphere.
A further advantage of the present invention is that the constant velocity joint stops the entry of contaminants into the constant velocity joint internal chambers.
A further advantage of the present invention is that the vent is resistant to grease, heat and is pliable thus allowing for the venting and closing off of the outside atmosphere to the internal workings of the constant velocity joint.
Still another advantage of the present invention is that the constant velocity joint vent is operable at high speeds and high temperatures sometimes found in prop shafts of automotive vehicles.
Other objects, features and advantages of the present invention will become apparent from the subsequent description and appended claims, taken in conjunction with the accompanying drawings.